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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        // 循环打印
        // 专门用来存放累加到一起的字符串星星
        var str = "";
        for(var i = 1; i <= 5; i++){
            // 循环体
            // console.log("★")
            str = str + "★"
        }
        console.log(str);
        // i = 1; str = '' + "★"
        // i= 2;  str = "★" + "★"  "★★"
        // i= 3;  str = "★★" + "★"  "★★★"
        // i= 4;  str = "★★★" + "★"  "★★★★"
        // i= 5;  str = "★★★★" + "★"  "★★★★★"
        // var a = "★";
        // var b = "★";
        // console.log(a + b)
        // console.log("★")
        // console.log("★")
        // console.log("★")
        // console.log("★")
        // console.log("★")
    </script>
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<body>
    
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